The Combo Deluxe Detail Brush kit contains 3 brushes which are nylon, brass and steel. The Nylon brush can be used to hard to reach places and on surfaces that might be scarred by brass or steel. The tough brass brush is great for cleaning off debris or removing rust on items like spark plugs, batteries or any similar items, the stainless steel brush is great for removing rust on the body or bumper of a vehicle.